Process of making cement and by-products



Patented Aug. 21, 1923.

UNITED STATES PATENT OFFICE.

EVALD ANDERSON, 01? LOS ANGELE CALIFORNIA, ASSIGNOB, BY MESHE ASSIGN MENTS, TO WESTERN PRECIPITATION COIIPANY, A, CORPOEATION OF CALIFORNIA.

racemes or maxim: cmzmwr AND ar-raonoc'rs.

Il'o Drawing.

To all whom it may concern:

Be it known that I, Emu) ANDERSON, a subject of the King of Sweden, and resident of Los Angeles, county of Los Angeles, State of California, have invented a new and useful Process of Making Cement and By Products, of which the following is a specificatiou.

This invention relates to a process for the manufacture of cement and recovery of potassium compound from the raw materials of,

tile potassium com ound and can be recov! ered by collecting t 1e fume passin from the cement kiln. I have found that t e amount of potassium compound so recovered may be considerably increased by the addition to the raw mix of a suitable amount of sodium chloride. This causes the potassium compound to be more completely volatilized or driven off from the cement making material in the clinkering operation, and also reduces the recombination of the volatilized potassium compound with the siliciousvincandescent dust to form diflicultly soluble compounds and thereby increases the solubility 3f the potassium compound in the collected ust.

My process may be carried out as follows:

To the partially ground cement raw material, including limestone and a suitable silicate such as clay. shale or feldspar. or mixtures thereof, and containing a small proportion of potassium compound, a suitable amount of dry sodium chloride is addedsay, about equal to the potassium content of the raw mix calculated as K 0. Thus, with the raw mix containing about 1% of K 0, there will be added about 1% of dry sodium chloride. The mixture is then ground to the usual fineness for cement and the resulting intimate mixture is burned to clinker in the usual way, coal being generally used as fuel, and in connection with the use of a coal flame for clinkering the cement my invention Application and Karen 14, 1917. mm Io. 164,700.

presents certain advantages, as hereinafter set forth, Other fuels may, however, be used in some cases. In such burning operation, the potassium compound is volatilized or driven off to an extent dependent on the temperature and the duration of heating in the iln, and I have found that under usual workin conditions of temperature and the rate of eed of the material throu h the kiln, the addition of the sodium chlori e produces a considerable increase in the amount of potassium compound driven off from the mix and enables a larger or cent of the potassium compound in t e raw material to be volatilized without requiring any departure from usual conditions of temperature, or reducing the capacity of the apparatus. The dust, in passing off from the kiln, is collected in any suitable manner, preferably by electrical precipitation in the manner set forth in the patent to W. A. Schmidt, No. 1,206,887, dated October 10, 1916. The

clinker resulting from the above ope atio may then be ground in the usual manner for the manufacture of cement.

\Vhen raw materials are used containing a considerable proportion of potassium, most I of the potassium compound is recovered with the dust collected from the fume passing over from the kiln, and in some cases, the potassium compound content of such dust is suflicient to enable it to be marketed directly as a fertilizer. If desired, however the potassium compound may be leached irom the cement flue dust so collected, 80 as to produce a more concentrated .IQduot, b eva o ration or concentration 0? the resuting solution. In some 1 cases, :partiqularl where coal is used in burning the cemen mix to clinker, a considerable 'roportion of the potassium com ound in t "e collected dust is in water-insoluEle form, by reason of recombination of the volatilized potassium compound with the silicious material in the dust. I have found that the use of sodium chloride in the mix has an important advanta e in reducing the amount of such recom ination and in thereby increasing the solubility of the potassium compound in the dust.

It is assumed that the potassium compound is liberated from the cement material as the oxide and that it then combines with whatever acid radicles present in the kiln gases, as well as with the siliceous ash particles from the fuel. In addition to vaporiii ized sodium clfilergdei' 111i urine miy'n wrotpeyc ent red! 0 2 salt added; tlie's ga es o C0%1t der l cii al iiafid iileiitricallj spfa di from the fuel, and CO from the fuel and potassiferous material from the kiln gases. cement metaaiel sethat he mammal-9 2a. iTl q e pce mqf m u fa uriag m lz i W pound in the-Sanka ai et-inay-m gl ieeue fii e.mi im m an 5h .53??? form of chlorides, su fates or other sulfur" radl'ic ceiiient, which cohsists"e'sseiit ial compound, carbonate or Si-liafifltfiuw: ya im gt l i igii gyififi sna wr wd'ate e calcareous I am aware that calcium chloride has material and silicates in proportion to form been used in the raw cemer'rffim'ux femthe hydraarliceeementa and including potassium purpose of increasing volatilization 0f the compound, heating the mixture by the compotassium ee'mpeupd. The-"use of sddium hustibn of coal producing aSll1C60uS ashm chloride? how'e'iier, hassevyai adnierltagsftheform.ofdust mixed wilh the fume of as compared Witlr'c'zilcium chloride." l n the potassiumi hearing; material liberated from 1 first lace, sod'ium' chlar ide ismeadily-'auail the-aforesaidmixture; by theaetion ofheat, able n' dry coiiditioti lihd isfeasily and-cow aiid supplying with therewumi-x, sufficient So nomical ly'niiir'eftl vi'ithftlfe ma -cement mate/= sodium jchloride to renct n ith the potas rial, \x 'heieas' calcihnichloride is:not adiiy amdr compound in the mix toefacilitate available in *d rf boiiditiiQi-i'fhrid is difii cii l't/tofli olatilization thereof, and to react with them n mix ex'ce'pt ir'i' the fftilin of sblutioii, and fih siliceous? ash? in i'theetfume to enable potas-e gg sucli"fornifits'addi'tihli' tb'ftl'! r I inconvenient and m njiany eases'i'mpcaeuew an the fumeliniwatersoluble form, and 001,- i i ble. awe sodium chloridefis -mimereadily-1ectin -yacnfume. I 1;, 1 w: volatiliidth ari'thecalciuihiihlbiikie and has 4! The herein described processof obtninit more 'tndenc td i tililtll iie uhchanged; ing a water sbluhlewpotassium eompou-ndini ,1 wheiea's thii lci'uii'i calende fiends"togde thenia n'ufactvire'ofzPortland cement whieh composefl Tlifinode cf b emien ef t he' consistsin subjecting the constituents o;fsodiun'i' chloriti" isli imsri'mal lyfpaemly "ehierpi ui-eland (-enieht to the direct action of the to an irii'tial",reaetiii' with th'ei lififlfibiiitfi preeminent combustion of coal i n the pres resultin'ir in'ui'e-bma anen ai stidhiidoicide Fence"ofi'the ash:contents of the coal siuiulr andca lgi uinfchliiiile tlfe latterbeingithcir"fiafieouslysubjecting said ash contents to the i decompqswwuyqnie heat fina wetun wiui teuitn te \iola'tiliaed nunt chloride nthe piitahsiuiii -corh otilifi fji'e seht fl th'"- cci nbining'witlra*sulistaiitial portion-of said mix id eiiumaaa e asit tii'ide qiuflassium aslVcontents whereby saidnash contents iis chl rid6 td"li"dii %ii"'ofi sotlle"t fiefiafii iflifl siibstanliihlyprevented?fron'iconibining ivith 4 L chldiide and sodiumoxidfi'vlip'el wllhbepi'es tlie soluble potiissiuln compounds and'fool-t 99 cnt in 'iffhe li ilng fise's iiic'o n i1t"witli anfy lecting 'the dus tfandfume\i'hiolnis givenefl" siliciotijdust prseiltith'ere'in .Tl'iei[5'eSiie*l}y Said constituent-SD e 1 i of sodiumtimeaa well as sediem chlorine i 5:" The process Uf -manufacturing Portland in the fewer vapori nitlfle"giissdirtiofitalct cenient 'and 're'cm'ering combined potassium with the sili'ciousdusfi tehd's to"i'ci'diice or which comprisesclinkering,by directfiring inhibit-,th' reacti'oir'ofthepotessiihnwhld "with powdered'eoal, a Portland cement mix ride with the silicious'i'riztterial; according to f containing potassiferous material and added r the laws of ihas s a'c'tioh, fttfdtheibyinsures sodium *chloritl. and recovering combined the reflantii'nl" 0f"m"re"" f thepo tiisiam" potassium from the dust and gesesqeaving 1 coiiipoudtl iii iyater our dfm,'"aspclias 'ihe kilnl '3 it sium chid'ride 6. Theprocess'df manufacturingPortland What rel-ma] 'i'sz T cement and recorering combined potassium l. Tli recess of makirig ceiiientend which comprises adding to a raw cement mix si ultaneou ljflpifqdiicinf"lfii ater" s'olulflle' containing"potassi'ferous material approxipo 'assl'timcompptind 'h h'ic consists add 'niately one per cent by weight of sodium ing to 'ra'i v ceiiient niiii, including-anappre-clilori(l, clinkering the mix in a rotary ceciable aim o u'nt' of potassiuni,fitbdiififl cl'ilomeat kiln fired with powdered coal, and reride, mount di-i s ondiiigcame amount eoi'ering combined potassium from the dust ofpotass'iurigi 'coinpou'ndln the cement mix; "and gases leavinp the kiln. suhjectin the mixture to 'sufiic ient heat to 7 The proccss of manufacturing Portland cause rolntilizationofpotassium compound cement and recovering combined potassium and collecting the fiinies 'resultitig from which comprises adding to a raw cement such volatiliyiation to proiliice potassium mix containing potassiferous m'atcrialsohearingniatelfial. i i "(linln chlorid in amount helow 3 per centby l li cprticesso'f nianiifactiiring Portland \vcight of the raw "nix. clinlcering the mix ceinclit and recorcring"coiiiliined'potassium in a rotary cement kiln fired with powdered which: comprises adding r ga ran} cein'ent coal. and recovering' combined potassium mix cimtainiiig' potassifer'ous material sofrom the (lust and gases leaving the kiln. (linm (lilorill in anioun tbelriw 3 llfil ccnt The hcrcin dcscribcd process of obtain by weight of the i:iw"'riii 'clinker'i'ngWhe ing water-soluble potassinrn compounds and =6 ralw mim i'd iiiiii compound to be produced and retained the constituents of :1 Portland cement mix by the direct action of the products of combustion from burning coal, in the presence of volatilized sodium chloride, and collecting and treating the dust and gases which are given oil by said constituents to recover the water-soluble potassium compounds contained therein.

9. The herein described process of obtaining a water-soluble otassium compound in the manufacture of ortland cement, which consists in subjecting the constituents of Portland cement to the direct action of the products of combustion of coal in the presence of the ash contents of the coal, simultaneously subjecting said ash contents to the action of volatilized sodium chloride present in approximately one per cent by weight to the weight of the Portland cement mix for combining with a substantial portion of said ash contents whereby said ash contents is substantially prevented from combining with the soluble potassium compounds, and collecting the dust and fume which is given off by said constituents.

10. The herein described process of obtaining a water-soluble potassium compound in the manufacture of Portland cement, which consists in subjecting the constituents of Portland cement to the direct action of the products of combustion of coal in the presence of the ash contents of the coal, simultaneously subjecting said ash contents to the action of volatilized sodium chloride present in below three per cent by weight to the weight of the Portland cement mix for combining with a substantial portion of said ash contents whereby saidash contents is substantially prevented from combining with the soluble potassium compounds, and collecting the dust and fume which is given off by said constituents.

11. The process of making cement clinker and simultaneously producing water soluble potassium compound which consists in adding sodium chloride to raw cement mix, contaming potassiferous material, subjecting the mixture to suflicient heat to form cement clinker and to cause volatilization of potassium compound, and collecting the dust and fume resulting from such volatilization to produce potassium bearing material.

12. The process of making cement clinker and simultaneously roducing water soluble potassium compound which consists in adding to raw cement mix containing potassiferous material, sodium chloride, in amount corresponding to the amount of potassium compound in the cement mix, subjecting the mixture to sufficient heat to form cement clinker and to cause volatilization of potassium compound and collecting the dust and fume resulting from such volatilization to produce potassium bearing material.

In testimony whereof I have hereunto set my hand, at Los Angeles, California, this 2nd day of March 1917.

EVALD ANDERSON. 

